Improvement in draft-regulators for stoves and furnaces



I J. BRIGGS. Draft Regulator for Stoves and Furnaces.

Patented Feb. 16, 1864.

I U ITED STATES PATENT O FIce} I JOHN BRIGGS, on ROXBURY, MASSACHUSETTS.

IMPROVEMENT IN DRAFT-REGULATORS FOR STOVE S AND FURNA CE S VSpecification forming part ofLetters Patent No. 4|,598, dated February16, 186-1. g I: k l

1b a whom zit may concern:

i 'Be it known that I, JOHN BRIGGS, a resident of. Roxbury, in thecounty of Norfolk and'State of Massachusetts, have made a new and usefulInvention for Regulating the Draft ofa Stove or Furnace; and I do herebydeclare the same to be fully described in the following specification,and represented in the accompanying drawings, of which- Figure 1 denotesa top view, Fig. 2 a side elevation, and Fig. 3 a vertical section, of ahot-air furnace and my invention applied thereto.

In the said drawings, A denotes the outer case of the air-heating spaceor chamber B, which surrounds astove or heating-furnace, (3, providednot only with an air-induction pipe, D, but a smokeor eduction pipe, E."

On the top of the case A there is placed an airtight drum, F, made oftin plate or other suitable material, it being furnished with a conicalor other proper-shaped standard, G, to serve as the fulcrum of one ortwo levers, H I, arranged horizontally on it, as shown in the drawings.This standard I usually make hol low and air-tight, and so rest orsupport it on the drum that its base may expand, as the head of the drummay, when the air or fluid within the drum may be heated. In this casethe standard becomes an auxiliary drum or expansion-vessel.

Each lever at one end is supported by a rod, K or K, which not onlyprojects upward from the top of the case A, or is hooked into a staple,a, extending from such top, but goes through the lever, and is providedwith a screw, 1), and a nut, 0, at its upper end or part, as shown inthe drawings.

From the other extremity of the lever a rod, L, depends, and is to beeither directly or in directly connected with a valve-stem, d. In thefigures the rod Lis represented as having a helical spring, 6,interposed between it and the valve-stem. hollow cylindrical vessel,open at bottom and closed at top, and provided with one or moreelongated openings, f f, made through its sides, such valve being causedto encompass and be capable of moving vertically on a cylindrical pipe,9, projected upward from the induction-pipe D, and being closed at itsupper end and furnished with a series of elongated, openings, h h, madethrough its sides.

The valve M of the stem is a The pipe g, at its lo wer end, opens intothe induction-pipe. A stop, i,s applied to'a wire,

70, projecting from the tube 9, as to be capable of being slid up anddown on such Wire, is to be inserted in one of a series of holes, It kIt, made in the side of the tube g,'the object of the stop being todetermine the height .to which the valve may be raised on the tube 9.The drawings also represent a valve, M, as applied to a tube, 9,extending up from and opening out of the eduction-pipe, the said valve Mbeing made with perforations or air inlets m m, and being dulysuspendedfrom the lever I.

The suspensiorrrod of each valve goes directly through its lever, butdoes not screw into it. Such rod, however, is provided at its upper partwith a screw, it, and nut 0, arranged on it and with respect to itslever, as shown in the drawings. The said screw and nut serve as a meansof adjusting the valve relatively to the lever.

Although I have represented in the drawings my invention as applicableto the induction and eduction pipes of the heating-stove of the hot-airfurnace, I wish it understood that it may be applied to only one ofthese pipes, or it may be applied to both of them, as may be desirable,in which latter case one expansion-drum will answer for both pipes. Itis sometimes the case that when the invention is applied to both of thepipes the regulation of the combustion of the fuel of the furnace, andof course that of the heat produced, will be better than if it wereapplied to one of these pipes only.

In the operation of the invention the air or fluid which may be Withinthe drum F will be expanded by the heat which may be conducted into itfrom the case of the air-chamber or furnace, the drum being so connectedwith or applied to such case or furnace as to enable the heat to bereadily conducted into it. The expansion of the airor fluid acting onthe upper head of the drum will raise the same, or cause it to be moreor less convex, and so as to elevate the fulcrum ot' thelever in amanner to produce a movement of the valvethat is to say, the valve ofthe induction-pipe will be moved so as to reduce the openings for theentrance of air into such pipe; but the valve of the eduction-pipe willbe raised in a manner to increase the area of its airopenings, in

order to allow more air to pass into the discharge-flue.

The expansion-drum, as shown in the drawings, has two heads, 2' s, thelower of which is not supported directly on the top of the case A, buton a short standard or seat-disk, t, resting thereon, and having adiameter less than that of the drum. This enables the lower head of thedrum to contract and curveinward and aidin producing a movement of thelever, such as would not be produced were the drum-head to rest at itsperiphery directly on the top of I the case A.

lhe spring placed between the stem of the eduction-pipe valve and rodofthelever thereof will operate to prevent breakage of the rod by thestrain of the lever while the valve may be elevated or brought upagainst its-stop. 7

Air or any expansive fluid or liquid suitable for the purpose may beused in the drum, it

being understood that the, said drum is to be filled with the same andto be made with either or both its heads, and particularly its upper Ihead, of a flexible material, such as will allow of the ready and properexpansion of the head under the expansion of the air or fluid induced byits absorption of heat.

I am aware that rods and various other contrivances have been used toregulate by their expansion by heat a valve or damper of aflue orpipe ofa stove or furnace, and therefore I make no claim to such, my inventionbeing an

